A local pizza shop claims its average home delivery time is 30 minutes. A sample of 40 deliveries had a sample average of 33 minutes. Assume the population standard deviation for the shop’s deliveries is 6.5 minutes.
a. Is there support for the shop’s claim using the criteria that were previously discussed?
b. Identify the symmetrical interval that includes 95% of the sample means if the true population mean is 30 minutes.